Cluster Flies
Colour: gray with golden hairs
Size: 8 – 10 mm
Cluster flies prove their nuisance during the winter when sunlight and warmth wake them from their slumber inside the walls and they collect in window wells or around light fixtures. While they do not cause any direct damage to your property, they are unsightly and the noise can be extremely bothersome, especially in the winter.


Cluster Fly Habitat
Cluster Flies are field insects, in the spring and will lay eggs on the soil and spend their summer outdoors. As colder weather approaches, they will seek protected over-wintering sites in such locations as hedge rows; under the bark of dead and dying trees; in the crevices of south-facing cliffs and rock faces; and within the cracks, crevices and voids of sheds, garages, barns, houses and other structures.

Cluster Fly Life Cycle
The adult flies lay their eggs on the soil, which contains earth worms. and as temperatures begin to increase the eggs hatch. The hatching larvae enter the worms to pupate and transition and emerge as adult flies. The life cycle is largely dependent upon prevailing weather conditions, in most circumstances 2 generations will be hatched in a year but in the case of a warmer summer season this can increase to 4 generations.

Cluster Fly Prevention
Seal and calk all openings in exterior walls, such as cracks and crevices near window and door frames. Close, repair and or replace all open and unscreened windows. Make sure all vents have screens to assure that Cluster Flies do not have access. In some cases of urban living it may be beneficial to consider a porch or double door entry way to avoid bringing them in with you when exiting or entering.
Fly Service Prep Guide
There are many things that should be done to prepare for a cluster fly treatment. For the full list of ways to make your cluster fly treatment successful, view our Fly Service Preparation Guide.
Pest ID
Do you have a fly problem in your home or business? Let us ID it for you!
Greenshield Pest Control is a family business that has been providing exceptional pest control services for more than 30 years.
We only employ licensed technicians and offer 24-7 emergency service!
Get In Touch
Toll Free: 1-877-838-7278
Kingston & Area: 613-389-3999
Brockville & Area: 613-342-4554
Quinte & Area: 613-966-6665
Perth & Area: 613-718-0001